Filter elements of pleated media are often arranged in a tubular construction. By the word “tubular”, it is meant a closed loop, which can be round, non-round, oval, elliptical, etc. The filter elements can be used in a variety of applications such as cleaning the air intake for compressors, or filtering the air in dust collectors, just to name a couple of examples. In many cases, the fluid to be filtered flows from the exterior, through the pleats, and into the open interior volume of the tubular construction. In many situations, it is desirable to support the pleated media from within the interior volume of the filter element in order to prevent the pleats from collapsing against themselves in the interior volume. When the tubular construction is oval or elliptical, the problem with having the pleats collapse against themselves is even more of an issue because of the geometry of the cross-sectional shape of the media construction.
One typical approach to supporting filter media within the interior of the filter includes using an inner filter liner. The inner filter liner is often made from metal and is porous or porous to allow fluid flow therethrough. There have been uses of non-metal as inner liners, as well.
In some environments which these filters operate, the environment is noisy due to operation of machinery, such as a generator, blower, or engine. Some filter constructions generate excessive noise due to air velocity, filter configuration, etc.
Improvements in media support and/or in ways to reduce noise are desirable.